Method and apparatus for roll straightening forged, cast and machined round parts



W. R. PUYEAR PARATUS Dec. 10, 1963 3,1 13,608 METHOD AND AP FOR ROLL STRAIGHTENING FORGED, CAST AND MACHINED ROUND PARTS 4 Sheets-Sheet 1 Filed March 29, 1962 SEE FIG.I.

FIG.2.

INVENTOR Wallace R. Puyear BY (m wm ATTORNEY .Dec. 10,- 1963 W. R. PUYEAR METHOD AND APPARA S FOR ROLL STRAIGHTENING FORGED, CAST AND MACHINED ROUND PARTS I Filed March 29', 1962 4 Sheets-Sheet 2 FIG FIG

INVENTOR Wallace R. Puyear BY 1,, (Mt *f-Govzfw FIG.6.

ATTORNEY Dec. 10, 1963 w.

METHOD AND APPARATUS R PUYEAR 3,113,608

FOR ROLL STRAIGHTENING FORGED, CAST AND MACHINED ROUND PARTS Filed March 29 1962 4 Sheets-Sheet 5 FIG.5.

I INVENTOR Wallace R.Puyear BY CLJLIwf-GwM ATTORNEY UYEAR Dec. 10, 1963 w. R. P

' METHOD AND APPARATUS FOR ROLL STRAIGHTENING FORGED, CAST AND MACHINED ROUND PARTS Filed March 29, 1962 4 Sheets-Sheet 4 FIG.7.

. INVENTOR Wallace R. Puyecar BY M ATTORNEY United States Patent Office hllifidd Patented Dec. 10, 19163 3,113,698 METHOD AND AFPTUS FUR liillll. STRAEGHTENENG FQRGED, CAST AND MACIHNED RGUND PARTS Wallace Ray Pnyear, Englewood, flhio (556? Moeeri Lane, Flint 7, Mich.) Filed Mar. 29, 1952, Ser. No. 183,427 17 Claims. (Cl. 15354) This invention relates to a method and apparatus for straightening round parts mdmore particularly, to roll straightening forged, cast and machined round parts.

Presently used methods and apparatus for straightening round parts about their taxes of rotation rely on the ability of an operator to detect a deformity in a round part and subsequently, determine the proper setting or adjustment of a straightening device in order to correct the deformity. This basic approach is, in itself, highly undesinable since no single setting is possible for producing round parts on a producton basis. Each straightening operation must, heretofore, be individually adjusted to the particular part being straightened.

With respect to forged round parts, due to prior art methods of straightening, each part must have an additional arnount of material diametrically disposed thereon to insure that a sufii'cient amount of material is present to permit a straight finished part to be manufactured from a bent or distorted forging.

With respect to cast round parts, these must also be made with an excess of diametrically disposed material, in view of prior art methods of straightening, to insure that a straight part may be manufactured from a bent or distorted casting.

Prior to this invention, straightening of round cast parts by detecting a deformation and overbending at this point was not generally applicable to castings. This is primarily because of the brittle nature of the grain structure of castings which results in a great many broken or damaged castings in response to overbending methods of straighten- 1n Present methods of straightening castings by impact in a conforming die while indexing the round parts in ninety degree increments of rotation about the axis to be straightened often require lleatin to prevent breakage and at best are time consuming hit and miss methods. In addition coining and brinnelling of the surface of the parts often results. Thus, subsequent machining to remove the excess material is difiicult due to the erratic surface characteristics resulting from straightening.

With respect to machined parts, such as those machined from bar stock, these, as in the case of cast parts, must also have additional matenial left on the diameters thereof. This is to permit an intermediate rough turning operation, whereby surface strains and skin deformations may be removed prior to the finishing operation. Subsequent annealing is then required for many types of steel alloys and then a complete straightening operation, all before the final or finishing operations are performed. The straightening operation, without the present invention, is again dependent on the skill of the individual operator in determining the location of a distortion or distortions in a given part and his subsequent ability to overbend the part to a degree whereby the proper amount of spring-back will render it straight' It is, therefore, an object of this invention to provide a method and apparatus for straightening forged, east and machined round parts whereby no specific operator skid or judgement is required.

Another object of this invention is to provide a method and apparatus for stnaightening forged, cast and machined round parts, whereby actual detection of distortion or deformity in each part is obviated.

Another object of this invention is to provide a method and appanatus for straightening forged, cast and machined round parts on a mass production basis, wherein each part is treated in an identical manner regardless of the individuality of pmticular distortions and deformities therein.

Still another object of this invention is to provide a method and apparatus for straightening forged, cast and machined round parts, whereby the necessity for excess diametrically disposed material on each part is obviated, resulting in a lower material cost per part.

Still another object of this invention is to provide a method and apparatus for straightening forged, east and machined round parts, whereby the part to be strtightened is subjected to a predetermined curvature along its axis of rotation and is subsequently rotated about that axis, the curvature being maintained throughout the rotation of the said part and being within the elastic limits of the material of said part.

Yet another object of this invention is to provide a method and apparatus for straightening forged, cast and machined round parts, whereby, simultaneously with the straigi tening of said parts, the grain structure of the material therein is stabilized.

These and other objects of this invention will become apparent with reference to the following specification and drawings which relate to a preferred embodiment of this invention.

In the drawings:

FIGURE 1 is an exaggerated diagrammatic illustration of a round part subjected to the method and apparatus of the subject invention;

FlGURE 2 is a top plan view of a detail of the invention;

FIGURE 3 is a side elevation, in partial cross section, of the invention;

IGURE 4 is a detail of FIGURE 3;

FIGURE 5 is a front elevation, in partial cross section, of the invention;

FIGURE 6 is a detail of FIGURE 5;

FIGURE 7 is a detail of FIGURE 5; and

FIGURE 8 is a detail of FIGURE 7 taken along line 8-8 therein.

The apparatus of the present invention generally comprises a system of rotating rollers which act to confine the round part to be straightened in a manner such that the axis of rotation about which the said part is to be straightened is subjected to a predetermined curvature. The part is then rotated about the axis of rotation thereof by the frictional forces developed by the appropriate rotary motion of the several rollers, the said axis of rotation being at all times constrained in the said predetermined curvature. The said curvature to which the said axis of the part is constrained is precalculated for the material and configuration of the part such that when released from the constrained condition, the part will have sufiicient spring-back to assume a straightened condition.

Referring in detail to the drawings, and more particularly to FIGURE 1, a round part Ill, which is to be straightened about the longitudinal and rotational axis thereof, is shown as being confined by three sets of rollers 12, 14 and 16, respectively. The longitudinal axis of the part, hereinafter designated as 18, as shown as assuming a curvature with respect to the theoretical or straightened axis 20 of the part it), which is parallel with the axes of rotation, not shown, of the various sets of rollers l2, l4 and 16. A plurality of arrows have been strategically placed in FIGURE 1 to show the curvature to which the rollers 12, 14 and to constrain the axis of the part 19.

Referring now to FIGURE 2, two sets of straightening rollers 12 and 14, are shown as mounted on a pair of driven parallel shafts 22 and 24, respectively, journalled i 3 in two common end housings 26 and 28. Both of the end housings 26 and 23 are mounted on a main load bed or platen 30 on the main frame of the straightening apparatus.

For purposes of maintaining proper alignment and rigidity under high compressive loads, each of the shafts 22 and 24 are provided with a centrally located support and journal bearing housings generally indicated at 32 and 34, respectively. The central bearing housings 32 and 34 are both mounted on the platen 30 of the apparatus.

The rollers 12 and 14 are positioned on their respective shafts 22 and 24 by means of a plurality of spacing collars 36 and 38, respectively. The sizes of the collars are varied such that the rollers contact predetermined areas on the par-t 10, whereby the proper curvature can be imposed on the longitudinal axis 13 as hereinbefore described in conjunction with FIGURE 1.

The rollers 12 and 14 are closely interleaved such that mating pairs of rollers comprising one roller from each set contact the part 10' in a given area thereof. The rollers 12 and 14 are thus staggered such that a roller from one set is immediately adjacent a corresponding roller from the other set.

Referring now to FIGURE 3, the upper rollers 16 are shown to be idler rollers individually mounted in kneeaction type pivoted yokes 4% pivoted at 42, on one side of the roller 16, to an upper bracket or supporting block 44 which is, in turn, adjustably mounted by T-shaped key and keyway connections 46 to a main upper platen or frame member 48. The bottom of the key 46 is provided with a threaded portion on which a take-up nut 47 is placed to hold the bracket 44 flush with the upper platen 48. The knee action of each yoke about the pivot 42 is limited by a pin and slot mounting at that end of the yoke 40 substantially diametrically opposite the pivot 4-2 with respect to the roller 16. This comprises a. pin 50' on the yoke 40 cooperating with an elongated confining slot 52 therefor.

Refer-ring additionally to FIGURES 5 and 6, each of the yokes 40 are shown as comprising a hood-type housing for the upper portion of the rollers 16, the rollers being mounted in the yokes 40 by means of fixed shafts 54 extending from one side of the hoodlike yokes 40 to the other, the said yokes 40 being bifurcated on cross section as shown.

Relative positioning of the upper rollers 16 with respect to the lower rollers 12 and 14 is accomplished by any suitable means for adjustably mounting each of the roller yokes 40 in the upper platen 4-8, whereby as shown in FIGURES 5 and 7, a plurality of variable width shims or chocks 55 may be inserted between the brackets 44 causing them to assume a predetermined spaced relationship along the keyways 46 to maintain the proper spacing between the rollers 16 held thereby in the yokes 40.

As detailed in FIGURE 6, suitable bearings such as the ball bearings 56 mounted between the fixed race 58 on the roller shaft 54 and the rotating race 69 on the roller 16, are provided for rotatably mounting the said rollers 16 on the shafts 54. Lubrication is provided for the bearings 56 via oil lines 62 and the cooperating flow channels 64- and 66 in the fixed shafts 54.

As particularly shown in FIGURES 3 and 5, each of the hoods or yokes 40 and the integrally mounted rollers 16 is biased about the pivot 42 by means of a pneumatic or hydraulic means 63, individually to each of the said yokes 40, mounted separately therefrom in each of the brackets 44.

Each of the hydraulic means 68 comprises a pressure feed line 70 which admits :a pressure fluid to a hydraulic cylinder 72. A piston 74 is housed in the cylinder 72 and includes an extended piston rod 76 which reaches out of the cylinder 72 through a suitable seal 73 to engage the upper surface of a corresponding yoke or hood 40 intermediate the pivot 42 and the pin-and-slot mounting ,see

4 50-52. Thus, by varying the pressure in the cylinder 72, the piston 74 and rod 76 force the yoke 40 and the roller 16 downward against the part 10, held by the lower or driven rollers 12 and 14, with a selectively variable force.

As also shown in FIGURE 5, the part 10 is confined against lateral play along the roller shafts 22 and 24 by means of locator blocks 79 adjustably positioned on the journal bearing housings 26 and 28.

The Roller Drive Means As shown in FIGURES 2, 5 and 7, the shafts 22 and 24, on which are mounted the lower or driven rollers 12 and 14 respectively, are driven by a corresponding pair of power shafts 80 and 82 which comprise the output shafts from a drive means 84 generally indicated in FIGURE 7. Each of the shafts 22 and 24 are connected respectively to the power shafts 80 and 32 by corresponding shaft couplings 86 and 88.

As shown in FIGURES 7 and 8 the drive means 84 comprises a motor 90 having an output shaft 92 with a drive pinion 94- thereon which simultaneously engages and drives a pair of gears 96 and 98 mounted on the power shafts 80 and 82, respectively. Both of the power output shafts 8t and S2 and the associated shafts 22 and 24 and their respective sets of rollers 12 and 14 are thus driven in the same direction of rotation by the motor 90 of the drive means 84.

Positioning the Idler Rollers While the upper or idler rollers 16 are not driven, as their designation implies, the main frame or upper platen 4-3 on which they are mounted is made vertically adjustable With respect to the lower platen 30 whereby an initial positioning of the rollers 16 with respect to the driven rollers 12 and 14 is made possible to accommodate parts 10 of a wide variety of diameters.

Hydraulic or pneumatic positioning means for the upper platen 48 is shown in FIGURE 7 in general schematic form. A main actuating cylinder 100 is positioned on a fixed frame portion 102 located above the upper platen 48. A power piston 164 having a power output rod 106 extending therefrom is mounted in the cylinder 100' for control-led vertical motion toward and away from the frame 102. The rod 106 extends from the cylinder 100 through a bushing 108 in the frame 102 and is connected to the top of the upper platen 48 by a suitable coupling means 110.

Extending vertically upward from the top of the upper platen 48 and through a bushing 112 in the frame 102 is a control rod 114 having a plurality of cam means 116 on the upper end thereof above the frame 102. The cammeans 116 on the control rod 114 selectively engage limit switches or control valves 118 and 120 on the actuating cylinder 100 which control, respectively, the lower and upper limits of travel of the pitson 104 in the said cylinder 100. Consequently, this controls the range of vertical adjustment of the upper platen 4S- and the idler rollers 16. The final adjustment of the idler rollers 16, as to the force of their engagement with the part 10 which is being straightened, is efiected by the individual hydnaulic or pneumatic means 68 as hereinbefore described with reference to FIGURES 3 and 5.

The proper alignment of the upper platen 48 with the lower platen 30 and the consequent alignment of the rollers 12, 14 and 16 is effected in the following manner.

A plurality of guide bushings 122, shown in FIGURE 7, are extended vertically through the upper frame 102 at selectively spaced positions. Each of the guide bushings 122 receives, to a close tolenance, a vertical guide post 124- free at its upper end and embedded at its lower end in the top of the platen 48 as shown at 126.

Referring now to FIGURE 3, additional vertically telescoping guides, comprising upstanding posts 128 on the lower platen 30 cooperating with close fitting externally concentric sleeves or bushings 134] depending from the upper platen 48,. are provided to achieve a high degree of registry between the upper or idler rollers 16 and the lower or driven rollers 12 and 14.

Cooling Means for the Apparatus The predetermined curvature to which the part is subjected by the relative positioning of the rollers 12, 14 and 16, as will be hereinafter more fully described with respect to the operation of the apparatus, and the constant flexing of the part it caused thereby, causes the part 119 to heat up. In addition, the frictional forces between the part 10 and the rollers 12, 14 and 16 cause a considerable amount of heat to be generated. Also, some parts are straightened while hot which severely augments the heat problem.

Referring to FIGURE 5, the shaft 22 on which the rollers 12 are held by means of keys 132 or the like is shown in cross-section as being typical of both the roller shafts 22 and 24.

The shaft 22 as shown is hollow and includes an internally concentric coolant supply pipe 134 which is held therein by internal journal bearings 136. The outer portions of the bearings 136 are fixed to the inner walls of the shaft 22 for rotation therewith while the inner portions of the bearings 136 are fixed to the coolant supply pipe 134. This permits the coolant pipe 134 to remain fixed while the shaft 22 rotates. Note in FIGURE 4 that a coolant pipe 134 is shown within the other roller shaft 24.

As shown by the dotted line arrows, the coolant pipe or tube 134 terminates in an open end so that coolant may fiow therefrom into the hollow shaft 22 in the area behind the left hand journal bearing 26. Note the dotted line arrows indicating the flow of coolant. The coolant comes from a suitable source (not shown) which is coupled to the coolant pipe or tube 134 via a pipe coupling and elbow combination 133. Any suitable means may be provided to exhaust the hot coolant from the hollow shafts 22 and 24.

Additional cooling is provided by radiation from the rollers themselves. As shown in both FIGURES 4 and 5, a plurality of radially disposed ribs or fins 141 are provided on the side faces of the rollers 12 and 14 so that excess heat will be radiated therefrom at a higher rate than from plane rollers of the same size.

An additional feature of the rollers 12, 14 and 16, which is necessary in order for them to remain true under the high working temperatures and pressures involved in the straightening of the round parts 11 is the provision of a hard tool weld facing 142 thereon as indicated in FIG- URE 5.

Operation The first adjustment to be made prior to the straightening of a plurality of like parts 10, as illustrated in FIG- URES 2 and 5, is to adjust the relative positions of the pressure rollers 12, 14 and 16 by means of the spacing collars 36 and 38 and the shims 55, respectively. All of the rollers cooperate in their properly adjusted relationship in sets of three. As shown in FIGURES 1 and 5, rollers of different diameters are used depending upon which area of the part 10 they are to be in contact with and in accordance with the predetermined overbending curvature to which the part 11? is to be constrained while undergoing the straightening process.

The next operational adjustment comprises the proper positioning of the locator plates or shoes '79 on the shaft end bearing blocks 26 and 28 to properly orient parts fed into the rollers. The spacing between the locator plates 79 depends on the length of the round parts 11 The driven rollers 12 and 14 are now rotated via the drive means 84 and output shafts 8d and 82 in a direction opposed to the direction in which the round parts 16 are to be fed into the apparatus in order to cause the parts 10 to properly nest in the rollers 12 and 14 rather than tend to eject therefrom. For example, in FIGURE 3 the rotation of the rollers 12 and 14 is shown as being counter-clockwise. Thus, the direction of feed for the parts 10 would be from left to right in FIGURE 3.

At this time, the flow of coolant, see FIGURES 4 and 5, through the coolant tubes 134 and 134 and into the hollow roller shafts 22 and 24, respectively, is initiated.

Assuming that the idler or pressure rollers 16 and the upper platen 48 are in a raised position out of contact prior to the feeding of each part 11? into the straightening apparatus, a part 11 is fed into the driven rollers 12 and 14 and the hydraulic or pneumatic system including the power cylinder 10% and the piston 104 is energized to lower the upper platen 48 so that the idler or pressure rollers 16 will contact the part 19.

The function of the individual pneumatic or hydraulic actuating means 68 for each yoke 40 of the pressure rollers 16 will now become more apparent. If, for example, because of the predetermined curvature imparted to the round part 19, one portion of the part is deformed into an eccentric position with respect to another portion thereof, a whipping action of the deformed or bent portion will occur due to its rotation while being constrained to that curvature. If the pressure or idler rollers 16 were all mounted on a common shaft, the whipping action of the part 10 would cause a bind ng and jamming interaction between the part 10 and the rollers 12, 14 and 16.

Although not specifically shown, the hydraulic or pneumatic actuating systems 68 for the yokes 40 of the idler rollers 16 we provided with suitable metering out means well known to the art which act as metered relief valves or the like in response to excess back pressure caused by an overload. In this case, the overload would occur as the part 10 started to bind in the rollers 12, 14 and 16. Thus, the particular roller 16 at which the binding action occurred could rise in response to the overload to thereby relieve that overload and prevent binding and jamming of the apparatus.

Additionally, each of the hydraulic actuators 68 is initi ally energized to apply a predetermined pressure to the rollers 16 and their associated rollers 12 and 14.

The curvature to which the parts 10 are constrained is a predetermined curve within the elastic limit of the material of the parts 10 as determined by the particular part configuration and the specific material from which it is fabricated.

By constraining the parts 10 to this curvature while they are simultaneously rotated, the material in the said parts 18* is subjected to an alternating deformation and elongation which provides a kneading action to the part material. Thus, the grain structure of the material of the parts 10 is stabilized by promoting a uniform grain flow therein.

Since the curvature to which each of the parts 11 have been constrained is within the elastic limit of the part ma terial and since that material is made homogeneous by the foregoing process, when the parts 10 are released from this constrained curvature they spring back to a straightened condition, all of the deformations and non-uniformities therein having been eliminated.

As can be seen from the foregoing specification and drawings, this invention provides a new and novel cost saving straightening method and apparatus for either forged, cast or machined round parts.

It is to be understood that the embodiments shown and described herein are for the purpose of example only and are not intended to limit the scope of the appended claims.

What is claimed is:

1. Means for roll straightening an elongated part having round portions symmetrical with the longitudinal axis thereof comprising first and second roller means including first and second parallel rotatable shafts, respectively, having a like plurality of rollers mounted thereon for rotation therewith, means for spacing said rollers on said shafts whereby corresponding rollers from said first and second roller means may be selectively positioned to contact preselected round portions of said part, said rollers of said first and second roller means being interleaved to form a cradle therebetween for supportably receiving said part, third roller means including a like plurality of individually mounted idler rollers thereon selectively positioned to contact said preselected round portions of said part to confine said round portions in compression between all of said roller means and actuating means for each of said idler rollers for individually controlling the force exerted thereby on said round portions of said part and drive means for rotating said first and second shafts and the said rollers thereon in the same direction of rotation, the rotation of said rollers in said first and second roller means causing said part and said idler rollers to rotate.

2. The invention defined in claim 1, wherein each of said rollers in said first, second and third roller means is of an individually preselected diameter which, in conjunction with all of the other of said rollers, will cause said rollers to constrain the longitudinal axis of said part in a predetermined curvature while said part is confined by said rollers.

3. The invention defined in claim 1, wherein each of said rollers in said first, second and third roller means is of an individually preselected diameter which, in conjunction with all of the other of said rollers, will cause said rollers to constrain the longitudinal axis of said part in a predetermined curvature while said part is confined by said rollers and each of said individual actuating means for said idler rollers includes means for automatically preventing the compressive force exerted by the associated one of said rollers on a particular round portion of said part from exceeding a predetermined maximum.

4. The invention defined in claim 1, wherein each of said rollers in said first, second and third roller means is of an individually preselected diameter which, in conjunction with all of the other of said rollers, will cause said rollers to constrain the longitudinal axis of said part in a predetermined curvature while said part is confined by said rollers and each of said individual actuating means for said idler rollers comprises an expansible chamber fluid pressure operated device, each said device including an overload responsive metering-out means for the operating fluid therein whereby the compressive force exerted by the associated one of said idler rollers on a particular round portion of said part is automatically prevented from exceeding a predetermined maximum.

5. The invention defined in claim 1, wherein each of said first and second roller means includes cooling means.

6. The invention defined in claim 5, wherein said cooling means comprises heat exchange means in each of the first and second rotatable shafts of said first and second roller means, respectively, and a plurality of radially disposed radiating fins on each of said individual rollers.

7. The invention defined in claim 1, wherein said first and second rotatable shafts, respectively, of said first and second roller means comprise elongated hollow cylinders and wherein each of said first and second roller means include cooling means comprising means for circulating a heat exchange fluid internally through the said first and second rotatable shafts and a plurality of radially disposed radiating fins on each of said individual rollers.

8. The invention defined in claim 1, wherein said means for spacing said rollers on said rotatable shafts comprises a plurality of collars concentrically disposed on said shafts intermediate said rollers and having a plurality of corresponding predetermined lengths for effecting said spacing.

9. The invention defined in claim 1, wherein said third roller means further includes a plurality of individual yokes for receivably supporting said idler rollers, each of said yokes including a fixed shaft spanned thereacross for rotatably mounting each of said idler rollers, and individual bracket means for supporting said yokes, said bracket means and said yoke being connected by a pivot connection and a pin and slot connection, respectively, adjacent diametrically opposite peripheral portions of each of said idler rolllers, whereby said idler rollers may be adjustably positioned by means of said yokes in a direction toward and away from said part.

10. The invention defined in claim 9, wherein said third roller means further includes a main support, means in said main support for adjustably receiving said bracket means for movement parallel to the axes of rotation of said idler rollers and shim means insertable between said bracket means for adjustably positioning said bracket means, yokes and idler rollers in predetermined position with respect to said part.

11. The invention defined in claim 1, wherein said third roller means further includes a plurality of individual yokes for receivably supporting said idler rollers, each of said yokes including a fixed shaft spanned thereacross for rotatably mounting each of said idler rollers, and individual bracket means for supporting said yokes, said bracket means and said yoke being connected by a pivot connection and a pin and slot connection, respectively, adjacent diametrically opposite peripheral portions of each of said rollers, whereby said idler rollers may be adjustably positioned by means of said yokes in a direction toward and away from said part; and wherein said individual actuating means for said idler rollers acts directly on said yokes intermediate said pivot connection and said pin and slot connection.

12. The invention defined in claim 11, wherein said third roller means further includes a main support, means in said main support for adjustably receiving said bracket means for movement parallel to the axes of rotation of said idler rollers and shim means insertable between said bracket means for adjustably positioning said bracket means, yokes and idler rollers in predetermined position with respect to said part.

13. The invention defined in claim 1, wherein said third roller means further includes a plurality of individual yokes for receivably supporting said idler rollers, each of said yokes including a fixed shaft spanned thereacross for rotatably mounting each of said idler rollers, and individual bracket means for supporting said yokes, said bracket means and said yoke being connected by a pivot connection and a pin and slot connection, respectively, adjacent diametrically opposite peripheral portions of each of said idler rollers, whereby said idler rollers may be adjustably positioned by means of said yokes in a direction toward and away from said part; and wherein said individual actuating means for said idler rollers acts directly on said yokes intermediate said pivot connection and said pin and slot connection; and further wherein each or" said rollers in said first, second and third roller means is of an individually preselected diameter which, in conjunction with all of the other of said rollers, will cause said rollers to constrain the longitudinal axis of said part in a predetermined curvature while said part is confined by said rollers and each of said individual actuating means for said idler rollers includes means for automatically preventing the compressive force exerted by the associated one of said idler rollers on a particular round portion of said part from exceeding a predetermined maximum.

14. The invention defined in claim 1, wherein said third roller means further includes a plurality of individual yokes for receivably supporting said idler rollers, each of said yokes including a fixed shaft spanned thereacross for rotatably mounting each of said idler rollers, and individual bracket means for supporting said yokes, said bracket means and said yoke being connected by a pivot connection and a pin and slot connection, respectively, adjacent diametrically opposite peripheral portions of each of said idler rollers, whereby said idler rollers may be adjustably positioned by means of said yokes in a direction toward and away from said part; and wherein said individual actuating means for said idler rollers acts directly on said yokes intermediate said pivot connection and said pin and slot connection; and further wherein each of said rollers in said first, second and third roller means is of an individually preselected diameter which, in conjunction with all of the other of said rollers, will cause said rollers to constrain the longitudinal axis of said part in a predetermined curvature while said part is confined by said rollers and each of said individual actuating means for said idler rollers comprises an expansible chamber fluid pressure operated device, each said device including an overload responsive metering-out means for the operating fluid therein whereby the compressive force exerted by the associated one of said idler rollers on a particular round portion of said part is automatically prevented from exceeding a predetermined maximum.

15. The method of straightening an elongated cast or forged metal article having at least three axially spaced round portions symmetrical with the longitudinal axis,

comprising the steps of providing a rotatable support for said article located at each of said round portions, each of said supports being capable of constraining the radial displacement of the article in all directions, exerting force on one of said round portions in one radial direction while exerting radial force on the other two portions in the opposite direction while rotating said article to urge the longitudinal axis of the article to assume a single bowed curvature.

16. The method as defined in claim 15, wherein the rotation is continued while the longitudinal axis is maintained in a substantially fixed predetermined curve.

17. The method as defined in claim 16, wherein the distortion of said article is within the elastic limit thereof.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3,ll3 608 December 10 1963 Wallace Ray Puyear It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 7, line 32, after "said insert me idler Signed and sealed this 16th day of June 1964.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. MEANS FOR ROLL STRAIGHTENING AN ELONGATED PART HAVING ROUND PORTIONS SYMMETRICAL WITH THE LONGITUDINAL AXIS THEREOF COMPRISING FIRST AND SECOND ROLLER MEANS INCLUDING FIRST AND SECOND PARALLEL ROTATABLE SHAFTS, RESPECTIVELY, HAVING A LIKE PLURALITY OF ROLLERS MOUNTED THEREON FOR ROTATION THEREWITH, MEANS FOR SPACING SAID ROLLERS ON SAID SHAFTS WHEREBY CORRESPONDING ROLLERS FROM SAID FIRST AND SECOND ROLLER MEANS MAY BE SELECTIVELY POSITIONED TO CONTACT PRESELECTED ROUND PORTIONS OF SAID PART, SAID ROLLERS OF SAID FIRST AND SECOND ROLLER MEANS BEING INTERLEAVED TO FORM A CRADLE THEREBETWEEN FOR SUPPORTABLY RECEIVING SAID PART, THIRD ROLLER MEANS INCLUDING A LIKE PLURALITY OF INDIVIDUALLY MOUNTED IDLER ROLLERS THEREON SELECTIVELY POSITIONED TO CONTACT SAID PRESELECTED ROUND PORTIONS OF SAID PART TO CONFINE SAID ROUND PORTIONS IN COMPRESSION BETWEEN ALL OF SAID ROLLER MEANS AND ACTUATING MEANS FOR EACH OF SAID IDLER ROLLERS FOR INDIVIDUALLY CONTROLLING THE FORCE EXERTED THEREBY ON SAID ROUND PORTIONS OF SAID PART AND DRIVE MEANS FOR ROTATING SAID FIRST AND SECOND SHAFTS AND THE SAID ROLLERS THEREON IN THE SAME DIRECTION OF ROTATION, THE ROTATION OF SAID ROLLERS IN SAID FIRST AND SECOND ROLLER MEANS CAUSING SAID PART AND SAID IDLER ROLLERS TO ROTATE. 